In the 'Game of Thrones' finale, this brilliant negotiation technique changes everything

On Sunday night's "Game of Thrones" season finale, "The Wolf and the Dragon," Jon Snow and Daenerys Targaryen redeem themselves as negotiators.

They meet with Cersei Lannister in the Dragonpit to persuade her that the army of the dead is a real and imminent threat. They are successful in convincing both her and her brother Jamie, the commander of her forces and her most trusted ally. And that ends up being enough to make a world of difference.

Yes, as viewers discover, Cersei plans to cross them by doubling down on her forces with a mercenary army from Essos and taking back her kingdom when her enemies are vulnerable. But she believes them about threat beyond the wall, and, because she does, she pledges to march her forces north. Her ploy ends up costing her Jamie, who had been the only sane voice left at her table.

How are her enemies so persuasive? First off, they come prepared, which is key to any successful negotiation. "You do not want to walk in there relying only on your intuition or gut instinct," says Harvard Business School professor and negotiation expert Deepak Malhotra.

Macall B. Polay | HBO

Lena Headey as Cersei Lannister and Nikolaj Coster-Waldau as Jamie Lannister, both among the highest paid "Game of Thrones" actors

Daenerys's team masterfully implements the show-don't-tell presentation. This isn't "death by PowerPoint," though; it's a compelling 3D spectacle, never short of visual aids or emotional appeal. The Hound sets loose the captured wight, which rushes straight towards Cersei. The queen clutches at the arms of her chair in fear.

In this moment, Jon and Daenerys achieve something they had struggled with earlier this season when they first met on Dragonstone: They connect with their counterpart. They make an impact. And that's crucial.

Just when the wight is about to pounce on Cersei, the Hound yanks it back and chops it in half, which only slows it down. The team offers a full-on tutorial on how to kill what is already dead. "We can destroy them by burning them," says Jon. "And we can destroy them with dragon glass."

Even Qyburn, Cersei's mad scientist, looks impressed. And it's safe to assume he's just about seen it all.

They do everything right. Cersei, in contrast, commits one of the most significant errorsyou can make during a negotiation: She makes a false promise.

"The more confidence your counterpart has in your honesty, integrity and reliability, the easier you will find it to negotiate," write Peter B. Stark and Jane Flaherty. Jon knows this. It's reflected in his inability to lie, even when it seems he could do it for all the right reasons.

Cersei has few close supporters or advisers left, only Qyburn, the silent Mountain and the unstable Euron Greyjoy. And who knows how long she will keep the Ironborn king around? Given his crude behavior and talking out of turn, it might be time to let him go.

The eventual consequence for Cersei is that Jamie, who has stood by her for years and recruited her talent like the sell-sword Bronn, finally leaves. No matter what she gains from her deceit, her loss of him could be catastrophic.